The present invention relates to a rail grinder.
The use of rail grinders for grinding irregularities in a rail of an existing railroad track is well known. In particular such rail grinders may be vehicles which move along a track and include a plurality of grind stones which grind the rail. The grinder vehicle may include a large number of grinding stones which are set at different angles in order to profile or reshape the cross-section of a rail. Certain kinds of rail grinders have heretofor been used to smooth out waves which are formed in a rail due to the repeated passage of trains over the rail.
As used herein, "grind stone" shall refer to the grinding element, regardless of its composition, which contacts a rail or other work piece for grinding thereupon. A grind stone is sometimes called a grind wheel.
As used herein, a "railroad track" shall include any track having a rail that constitutes a road pathway for a vehicle.
Existing rail grinder arrangements have been generally subject to one or more of several disadvantages. In particular, they have had difficulty smoothing out the waves in the track when the waves are longer than the diameter of the grind stone. That is, the grind stone may grind down into the dips into the rail instead of simply grinding off the peaks in the wave on the rail. Although larger grind stones may help with this problem, power and other constrants prevent one from using an especially large grind stone.
Prior grinders often have an additional disadvantage in that many of them require the use of "feelers" in order to allow the grinding wheel to follow the track at curves such that chordal error is minimized. Such feelers may be small rollers which support the grinding stones in an isolated fashion from the main suspension of the vehicle. On the other hand, those grinders which are mounted from the main suspension of a vehicle and near the vehicle wheels are disadvantageous in that the grinders are not isolated from the suspension such that up and down movement of the suspension may cause the grinder to amplify (by further grinding) waves which are already existing in the rail.
A further disadvantage of numerous of the prior grinder vehicles and, more generally, various grinder machines, is that there is a lack of flexibililty in setting up the angle of grinding. That is, the range of angles over which the grinder may be set is often quite limited. Changing the angle of grinding often changes the distance to the rail. Moreover, setting of the angle of the grinder may require the unbolting and bolting of different components, this being a rather time consuming step. Further, setting of the angle and positioning of the grinder in the correct position relative to the rail may require separate steps and often requires the operator to leave the vehicle cab. Setting the vertical position of a grinder often requires a separate step from setting its horizontal position.
Another disadvantage of some prior grinders is that the grinding power delivered to the rail may be quite inconsistent.
Some prior grinders require precision machine surfaces adversely affected by the environment.
Those prior grinders which allow some grinder orientation changes by operator control from a vehicle cab often are limited to specific angles of grinding.
A further disadvantage of numerous prior grinders is that those that allow grinding for wave control often are not suitable for profiling, whereas those which are adapted for profiling are generally not well suited for smoothing out the waves in the rail.
Another disadvantage common to numerous prior grinders is that they are not suitable for use at crossings, switches, turnouts, and on specially shaped rails or specially laid rails such as used where a track crosses a road or crosses another track.
Those prior grinders which allow adjustment of grinder angle and/or position are often disadvantageous in that they may assume improper positions such as having the grind stone beneath the ball of the rail. On the other hand, use of feed stops to help avoid having a feed jack move to such a position may complicate the design as the feed stops generally must be adjustable.